Incandescent lamp.



D. G; MACDONALD- INGANDESGENT LAMP.

APPLICATION FILED JULY 11, 1910.

Patented Jim 27, 1911.

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INGANDESGENT LAMP.

2 SHEETSSHBET 2 Patented June 27, 1911.

APPLICATION FILED JULY 11, 1910.

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UNITED STATES PATENT OFFICE. I

DONALD G. MACDONALD, 0F SYDNEY, NOVA SCOTIA, CANADA, ASSIGNOR 0F TWENTY- FIVE ON E-HUNDREDTHS TO ADELARD LA PIERRE, OF SYDNEY, CANADA.

INGANDESCEN T LAMP.

Specification of Letters Patent.- Patented June 27, 1911. Application filed July 11, 1910. Serial No. 571,471.

To all whom it may concern:

- Be it known that I, DONALD G. MAC- DONALD, a subject of the King of Great Britain, residing at Sydney, Nova Scotia, Dominion of Canada, have invented certain new and useful Improvements in Incandescent Lamps; and I do declare the followin to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in incandescent lamps.

One object of the invention is to provide a lamp havmg a plurality of filaments whereby should one of the same become broken or burnout, the others will continue to burn and the lamp thus used at a reduced illuminat-ing power.

Another object is to provide a lamp having a plurality of filaments and means whereby the current may be passed through one or more of the same, thereby controlling or regulating the candle power or illuminating capacity of the lamp.

With the foregoing and other objects in view, the invention consists of certain novel features of construction, combination and arrangement of parts as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings, Figure 1 is a side view partly in section of a lamp showing one form or arrangement of my invention; Fig. 2 is a diametrical sectional view of the lamp shown in Fig. 1; Fig. 3 is a view similar toFig. 1 showing a modified construction and arrangement of the lamp; Fig. 4 is a diametrical sectional view of the upper portion of the lamp shown in Fig. 3;

' Fig. 5 is a diametrical sectional view of a simplified form of the lamp showing thewires arranged similarly to the arrangement shown in Fig. 4 but omitting the switch shown in the latter figure; Fig. 6 is a diametrical sectional view of another simplified form of the invention. 7

Referring more particularly-to the form of the lampshown in Figs. 1 and 2, 1 denotes the bulb or globe of the lamp, the upper end of which is depressed, as. shown at 2, and has. formed therein a centrally disggsced-upwardly projecting tubular stem 3.

ured to the upper end of thevbulb is the usual or any suitable form of plug 4, by means of which the lamp is engaged with a socket. The plug 4 is here shown in the form of a screw plug and has in its upper end the usual contact disk or terminal 5.'

Arranged around the outer side of the tubular stem and spaced a suitable distance apart are a series of terminal rings or bands 6, with each of which is connected one end of terminal or currentconducting wires 7,

.9 is preferably in the form of a narrow plate or bar of suitable metal and has one edge preferably formed on a curve, whereby the switch may be successively engaged with the contact points 8 011 the bands 6. Any suitable means may be provided for operating the switch 9, said means being here shown and preferably consisting of cords or chains 11, which are passed through apertures 12 in the opposite sides of the plug 4 and have their inner ends connected to the upper end of the switch. To the outer ends of the cords or chains 11 are connected knobs 01' balls 13, by means of which the cords may be conveniently grasped and pulled in the proper direction for swinging the switch back and forth into and out of engagement with the con tact points 8 of the terminal bands 6. Adapted to be engaged with the tubular stem 3 is a filament supporting tube 14 formed of glass or other suitable non-conducting material. the upper stem engaging portion thereof is secured a series of upper filament supporting bands 15 which are'spaced suitable distances apart and have secured thereto at diametrically opposite points radially projecting filament supporting rods 16 of suitable current carrying capacity. The rods 16 gradually decrease in length from the upper to the lower rod and to the outer ends To the tube 14 adjacent of the rods are connected the upper endsof a-series of filaments 17 which are preferably of varying candle power, and which have their lower ends connected to the outer ends of a series of filament supporting rods 18, which are arranged one above the other and decrease in length from the lower to the upper rod as shown. The inner ends of the rods 18 are all secured to a single supporting band 19 secured to the tube 11 adjacent its lower end, as shown. The current conducting wires 7 from the terminal bands 6 on the stem 3 pass upwardly and thence inwardly and down through the upper portion of the tube 14, and have their lower ends passing through suitable apertures 20 formed in the opposite sides of the tube 14: above each of the filament supporting bands 15. The outer ends of the current conducting wires 7, after passing through the apertures 20, are connected with the bands 15 and through the same and the supporting rods 16 are electrically connected with the filaments 17. The incoming current conducting wire 21 of the circuit is connected at its lower end to the .lower filament supporting band 19 and through the same is electrically connected with all of the filaments 17. The conducting wire 21 passes into the lower end of the tube 14 from the band 19 and thence upwardly through the tube, and is connected at its upper end to the contact or terminal disk 5 in the upper end of the plug 4:. The return'or outgoing current conducting wire 22 is connected at its inner end to the switch supporting'band 10 and passes through or is connected with the threaded metal portion of the plug in the usual or any suitable manner as shown at 23, whereby, when the plug is engaged with the socket, the contact or terminal plate 5 will make connection with one of the main current conducting .wires while the other wire will be connected to the metal portion of the socket which comes in contact with the threaded portion of the plug, thus connecting the conducting wires 21 and 22 to the main conducting wires of the lamp. By connecting the current conducting wires 7 separately with the filament supporting bands 15 and with the terminal bands 6,the circuit may be completed in any number of the filaments by means of the switch 9 by swinging the latter into engagement with one or more of the contact points 8 on the bands 6, said switch being in electrical connection with the return wire 22 through the supporting collar 10, as hereinbefore described. By providing filaments of varying candle power, the illuminating capacity of-the lamp may be regulated through the switch connection between the separate filaments and the current conducting wires as will be readily understood.

In Figs. 3 and 4 of the. drawings is shown a lamp constructed and arranged similarly to the lamp shown in Figs. 1 and 2. In the form of lamp shown in Figs. 3 and 4, two sets of filaments 25 are provided, said filaments both. being in electrical connection with the same current conducting wires so that the filaments burn together. By providing two sets of filaments, as shown, should one of the same burn out or be broken, the lamp may still be used at a reduced illuminating power. In connection with this arrangement of filaments is shown a switch mechanism whereby the current may be turned on and off. The switch mechanism referred to comprises a switch 26 which is pivotally connected at its lower end to a switch supporting band or collar 27, which is in electrical connection by a conducting wire 28 with the casing of the plug, in the same manner as I shown and described in Figs. 1 and 2 of the drawing. The switch is adapted to be brought into engagement with a contact plate 29 arranged on and having an electrical connection with the outgoing or return wire 30 from the filaments, the upper end of which, after being brought out of the upper end of the tube 24, is coiled several times around the outer side of the tubular stem of the lamp as shown. When the switch is swung over into engagement with the contact plate 29, it will be seenthat the electrical connection will be complete between the return wire 28 and the wire 30 from the filaments through the switch supporting band or collar 27. In this form of the device, the switch is operated by cords or chains 31 connected at their inner ends to the upper end of the switch bar and which pass through suitable apertures in the plug and are provided on their outer ends with knobs or balls 32.- In the form of the lamp shown in Figs. 3 and 4, the incoming current conducting wire 33 is arranged in the same manner as shown in the first figures of the drawing.

In Fig. 5 of the drawings, the lamp is constructed and arranged in the same manner as shown and described in connection with Figs. 3 and 4 of the drawings, except that the switch arrangement is dispensed with and the return wire 34 from the upper filament supporting band passes directly from the upper end of the filament supporting tube'andstem of the lamp to the side of the plug with which it is electrically connected,

as previously described.

In Fig. 6 of the drawings is shown a modification of the simplified form of the lamp. In Fig. 6, the filament supporting tube 35 is shown as being engaged or slipped onto the tubular stem 36 of the lamp, said stein being shown in this instance as projecting downwardly from the upper end of the lamp bulb. To the lower end of the tube 35 areseeured clips 37 having arranged thereon binding posts or'screws 38 and 39. Tothe binding screw 38 is connected one end of the I ceases at its lower end to the binding screw 39 and at its upper end to the outer portion of the plug of the lamp, as shown at 43. On the tube 35 is arranged an upper filament supporting band 44 and a lower filament supporting band 45, provided with filament supporting rods 46' arranged as previously described and connected at their outer ends by the filaments 47. The lower filament supporting band 45 is connected to the binding post 38 by a short conducting wire 48, while the upper filament supporting band is connected to the binding post 39 by the cur- .rent conducting wire 49, which passes upwardly from the band 44 over and into the upper end of the tube 35, and thence downwardl through the same-and is connected at its ower end to the post 39, as shown; In this form of the device, the current enters the lamp through the terminal 41 and conducting wire 40 to the post 38 and thence through the wire 48 to the band 45 and filament supporting rods 46, from said rods through the filaments 47 to the upper supporting rods 46 and band 44, whence the current passes through the conducting wire 49 to the terminal post 39 and then thrdugh the return wire 42 to the plug of the lamp.

The end of the tubular stem 3 is closed and the wires sealed where they pass through said closed end in the various forms of the lamp shown and between the filament supporting tube and the inner wall of the tubular stem is preferably arranged a packing 50 of asbestos which will prevent possible vibration of the filament supporting tube.

From the foregoing description taken in connection with the accompanying drawings, the construction and operation of the invention will be readily understood without requiring a more extended explanation.

Various changes in the form, proportion and the minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of this invention as defined in the appended claims.

and adapted to be swung Having thus described my invention, what I claim is 1. The combination of a bulb having a tubular stem,

a tubular support extending from said stem Within the bulb, a plurality of independent terminal bands on the stem,

a plurality of filaments carried by the tubular support, conductors connecting the filaments with the respective terminal bands, a main conductor having a common connection with the lower end of all the filaments, a switch mounted on the tubular stem and arranged to contact with one ora plurality of the terminal bands, and a second main conductor connected to said switch.

2. The combination of a bulb, a tubular nonconducting support therein, a plurality of conducting bands on said support, con ducting arms radiating from said bands, filaments secured to and extending between said arms, and line conductors connected with-the bands of the tubular support.

3. In an incandescent .lamp, a bulb, a tubular stem arranged in one end thereof,

a series of terminal bands arranged on said stem, a filament supporting tube adapted to be engaged with sa1d stem, a series of independent filament supporting bands arranged on the upper portion of the tube, a common .filament supporting band arranged on the lower portion of the tube, upper and lower series of filament supporting rods connected respectively'with said upper and lower bands, a series of filaments connected to the outer ends of said rods, a main conducting wire arranged through said tube and connected with said common filament supporting band on the lower end of the tube, a series of current conducting wires to independently connect the upper filament supporting bands with the terminal bands on said stem, a return conducting wire, and a switch connected with said return wire into engagement with one or more of sa1d terminal bands whereby an electric. circuit is completed through one or more of said filaments.

In testimony whereof I have hereunto set my hand in presence of two subscrlbing witnesses.

DONALD G. MAcDONALD. -Witnesses:

ANNA M. MACKENZIE, CHARLES W. ROWLINGS. 

